This application relates to tension sensors, and in particular, a seat belt tension sensor.
Vehicular air bags play an important role in restraining a seat occupant in vehicular crash situations. However, and in some applications, it may be desirable to suppress the deployment of an air bag. In addition, the deployment of an air bag corresponding to an unoccupied seat represents an unnecessary repair expense.
Vehicles are provided with seat restraint systems such as a seat belt in order to restrain an occupant in a seat of the vehicle. In some vehicles, the seat restraint system may be a lap belt, a shoulder belt, or both. Occasionally, the lap belt and shoulder belt are connected together at one end. The seat restraint system includes a latch plate at the connected end. The seat restraint system also includes a buckle connected at one end by webbing or the like to the vehicle structure. The buckle receives the latch plate to be buckled together. When the buckle and latch plate are buckled together, the seat restraint system restrains movement of the occupant to help protect the occupant during a collision.
Some inflatable restraint systems want input information as to the occupancy of the vehicle seat. Deployment of the inflatable restraint may partially depend on information supplied by sensors in the seat, such as a sensor that would determine the weight of an object in the seat.
When a child seat is placed in the seat and cinched down, the sensors may need a way to distinguish between a large mass and a child seat. Typically, when a child seat is used, there will be high tension in the seat restraint system. Comfort studies have typically shown that a human occupant would not wear their seat restraint that tightly. Readings on seat restraint tension can help to decide the deployment characteristics of the inflatable restraint.
Thus, it may be desirable under certain conditions to provide information to a control module to help to determine the difference between a child seat or an occupant.
A method and apparatus for detecting the tension in a seat belt. The detected tension corresponding to a tension consummate with a tension created when a child safety seat is secured by the seat belt. The sensor then produces a signal which instructs a controller to suppress the deployment of an air bag.
The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.